> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Demo Sourcing a Module From the Terraform Registry
> This guide demonstrates sourcing an S3 bucket module from the Terraform Registry using Terragrunt for simplified version management.
In this guide, we’ll demonstrate how to source the same S3 bucket module from the Terraform Registry using Terragrunt. Instead of pulling the module from GitHub, we switch to the `tfr:///` prefix and pin a specific version. This approach simplifies version management and leverages the official [Terraform Registry](https://registry.terraform.io/) distribution.
## Why Use the Terraform Registry?
| Source Type | Prefix | Example Address |
| ------------------ | ----------------------------- | --------------------------------------------------------------------------- |
| GitHub | `git::https://github.com/...` | `git::https://github.com/terraform-aws-modules/terraform-aws-s3-bucket.git` |
| Terraform Registry | `tfr:///` | `tfr:///terraform-aws-modules/s3-bucket/aws?version=4.1.2` |
Pinning module versions (e.g. `?version=4.1.2`) ensures reproducible builds and prevents unexpected changes when upstream modules are updated.
## terragrunt.hcl Configuration
Create or update your `terragrunt.hcl` file with the registry source and input variables:
```hcl theme={null}
# terragrunt.hcl
terraform {
source = "tfr:///terraform-aws-modules/s3-bucket/aws?version=4.1.2"
}
inputs = {
bucket = "my-unique-bucket-name"
acl = "private"
public_access_block = {
block_public_acls = true
block_public_policy = true
ignore_public_acls = true
restrict_public_buckets = true
}
}
```
The syntax breakdown:
* `tfr:///` — Registry prefix (two slashes for delimiter + one slash to start address).
* `namespace/module_name/provider` — Module path on the Terraform Registry.
* `?version=x.y.z` — Query parameter to lock the module version.
## Initialize and Apply with Terragrunt
Run the following commands to download the module and provision your S3 bucket:
```bash theme={null}
$ terragrunt init
[terragrunt] INFO: Downloading module...
...
$ terragrunt apply --auto-approve
...
Apply complete! Resources: 1 added, 0 changed, 0 destroyed.
```
## Verify the S3 Bucket
Use the AWS CLI to confirm that your bucket exists:
```bash theme={null}
$ aws s3 ls
2023-08-15 12:34:56 my-unique-bucket-name
```
Bucket names must be globally unique. If you encounter an error about the bucket already existing, choose a different name.
## Links and References
* [Terragrunt Documentation](https://terragrunt.gruntwork.io/docs/)
* [Terraform Registry: S3 Bucket Module](https://registry.terraform.io/modules/terraform-aws-modules/s3-bucket/aws/latest)
* [AWS CLI S3 Commands](https://docs.aws.amazon.com/cli/latest/reference/s3/index.html)